Liquid pump



C. BROWN LIQUID PUMP May 12, 1931.

2 Sheets-Sheet- 1 Filed Nov. 1, 1930 /NVNTOR M m ZgiQA/m May 12, 1931.

C. BROWN LIQUID PUMP Filed Nov 1. 1950 2 Sheets-Shei 2 I Fig. 3.

Fig. 4.

Patented May 12, 1931 UNITED STATES PATENT OFFICE CLEMENT BROWN, 0F PERRY BARR, BIRMINGHAM, ENGLAND. ASSIGNOR TO AMALGA- MATED GARBUBETTERS LIMITED, OF PERRY BARR, IBIRMINGHANI, ENGLAND LIQUID PUMP Application filed November 1, 1930, Serial No. 492,775, and in Great Britain October 31, 1929.

This invention relates to apparatus for elevating or impelling the liquid fuel in an automobile for the purpose of lifting the petrol from the tank to the carburetor when 5 the tank is at a lower level than the carbureter. Conditions as to the necessary rate of flow and otherwise in such and similar circumstances vary between wide limits but it is always necessary that the potential supply of petrol should be maintained in ex cess of the requirements of the carbureter. The object of the present invention is to provide apparatus for this purpose which will deliver an excess of liquid fuel at constant or semi-constant pressure and which will function effectually under widely differing conditions.

In order that this invention may be'clearly understood and readily carried into practice reference may be had to the appended explanatory drawings in which one form of the invention is shown as applied to an automobile of which Figure l is a sectional elevation of a pump device according to the resent invention.

Figure 2 is a sectiona plan of the apparatus shown in Figure 1 the plane of section being on line 22 of the figure last mentioned.

Figure 3 is a sectional elevation of the device shown' in Figure 1 the lane of section being on line 33 of the gure last mentioned.

Figure 4 is a fragmentary elevation similar to Figure 1. 1

In the particularembodiment of the present invention shown in the drawings the force pump or impulsion element takes the :form of a diaphragm a actuated from a cam on the cam shaft of the engine or from another suitable operating part, the diaphragm a forming the oscillating portion of a pump chamber 6. The pump chamber 1) receives liquid from the source of supply 0 through suitable passages and by way of one nonreturn valve d and delivers the liquid to the float chamber through a second non-return valve 0.

Leading out of the outlet port 6 is a conduit h communicating with the control pump and moves against the action of the spring w when influenced by such pressure.

The pressure exteriorly of the control chamher is maintained atmospheric by the provision of a suitable vent m The diaphragm g operates a slide valve is centrally disposed in the apparatus which slide valve checks and/or diverts the flow of liquid through the pump as hereinafter described.

The normal position of the slide valve is is that shown in Figure 1 and the valve takes up this position when there is either suction in the control chamber f or else there is insufficient pressure there to force the diaphragm 9 against the action of the spring as. This is the position that the valve -takes up when the carbureter is requiring all the liquid that the pump can supply and when in this position the slide valve is does not affect the normal working of the pump in any way, the base of the slide valve being seated on a ball valve h positioned at the base of the hollow stem. When however (as will almost always be the case, in use) the potential supply de-- livered by the pump is in excess of the requirements of the carbureter a pressure will develop in the control chamber 7 sufiicient to press the diaphragm 9 against the action of the spring ac. This will cause the upin the control chamber after the supply has been thus cut on, the diaphragm g will-be further displaced and the slide valve k will be further lifted, thus opening up communication between the inlet and the outlet ports of the pump, via the conduit k for manipulating the diaphragm a resilient bufier such as a spring j or similar devices.

The modification shown in Figure 4 differs from that shown in Figure l in the fact that whereas in Figure l the pump diaphragm. a is provided with anactuating stem 2 which may directly be engaged by a cam the equivalent element 4 in the modification shown in Figure 4 is actuated indirectly through the intermediary of a lever 5 appropriately incorporated.

From the above description the operation of the apparatus when in use will be evident and it will be seen that the pressure at which the liquid is to be supplied can be predetermined by varying the compression strength of the spring :22.

It will be understood moreover that the invention is not limited to use in an automobile as has been described as an example, but is applicable to any circumstances wherein liquid is to be supplied at a predetermined constant or semi-constant pressure.

As an alternative to the details shown any convenient form of pump orimpulsion element can be utilized and the control slide valve can takeother forms than that shown in the drawings.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that what I claim is 2- Apparatus for pumping liquids, comprehending in combination a casing providing a pump chamber, a pumping diaphragm in said chamber, a supply conduit leading to said pumping chamber, a discharge line leading from said chamber, a control chamber in said pump casing communicating with said discharge line, a control dia-- phragm in said control chamber subjected to pressure of liquid in the discharge line,

a slide valve connected to said ,control charge valve in the discharge line betweenthe pump and the control chamber, and a by-pass port in said slide valve communicating between the control chamber and the supply line and normally closed, whereby excessive pressure in the discharge linewill move the control diaphragm and slide valve to first, move the supply port out of register with the supply line, and increased excessive pressure moves the slide valve further to open the by-pass port.

In witness whereofI afiix my si nature.

CLEMENT BR WN. 

